Preparation method of diamond grinding wheel for wafer Notch groove grinding

Abstract

The invention discloses a preparation method of a diamond grinding wheel for wafer Notch groove grinding, which comprises the following steps: various raw materials of the diamond grinding wheel are obtained according to a preset formula, the various raw materials comprise a diamond grinding material, metallic bond powder and an additive, and the additive comprises one or more of ceramic powder and resin powder; mixing the various raw materials to obtain a mixed material; the grinding wheel base body is put into a mold, and the mixed material is put into the mold, so that a mold with a grinding wheel green body is obtained; the mold with the grinding wheel green body is subjected to hot pressing sintering and heat preservation, then the mold is detached, and a grinding wheel blank is obtained; and the grinding wheel blank is machined and trimmed, and the diamond grinding wheel is obtained. According to the diamond grinding wheel prepared through the method, ultra-precision grinding machining of a wafer Notch groove can be achieved, the service life is prolonged, and the machining precision is improved.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-precision grinding of semiconductor wafers, and in particular to a method for preparing a diamond grinding wheel for grinding a notch groove of a wafer. Background Art

[0002] Silicon carbide (SiC) is a compound semiconductor material composed of silicon (Si) and carbon (C). It has a very strong bonding force and is very stable in terms of heat, chemistry and mechanics. As a typical representative of the third generation of semiconductor materials, SiC has a larger bandgap, higher breakdown electric field, higher thermal conductivity, higher electron saturation rate and higher radiation resistance. It is more suitable for making high-temperature, high-frequency, high-radiation and high-power devices. It has been widely used in automotive electronics, industrial semiconductors and other fields.

[0003] Semiconductor circuits were originally manufactured in the form of wafers, which are round silicon wafers used to make semiconductor circuits. Many independent circuits can be built on the wafer. Positioning and alignment are required in many links of wafer manufacturing, such as photolithography, etching, doping, etc. These processes require precise positioning of the direction of the wafer to ensure that each step of the process is consistent with the previous step.

[0004] The flat edge or groove of the wafer (i.e., Notch groove, see Figure 1 ) design, which is mainly used to determine the type, doping and crystal orientation of the wafer during the manufacturing and processing of the wafer, so that the wafer can be cut and positioned more efficiently during the production process, thereby improving production efficiency. The Notch groove is a concave structure with a certain angle and depth. The national standard stipulates that the depth of the Notch groove (V-shaped groove) is 1mm and the angle is 90°. Through these flat edges or groove marks, the specific crystal orientation of the wafer can be quickly determined, thereby guiding subsequent wafer processing operations. Crystal orientations include the common (100), (110) and (111) crystal orientations. The surfaces of wafers with different crystal orientations have different physical and chemical properties, which will have different effects on the electrical properties and etching process of the device. Therefore, the correct identification of the crystal orientation must be ensured during the processing. On 2-inch to 6-inch wafers, the flat edge is used as an alignment reference point, and the process equipment can easily place the wafer in the correct position. The mainstream 8-inch or 12-inch wafer uses the notch as an angle reference to establish coordinates to mark the physical position of each die (crystal, which is the small piece into which the wafer is cut).

[0005] It should be noted that the notch is a special design on the edge of the wafer. Compared with the flat edge, the notch is smaller, does not occupy the effective area of ​​the wafer, and can provide more reference points, which helps to position the wafer more accurately and efficiently. Modern automated equipment can more easily identify and process the notch. Therefore, compared with wafers with flat edges, wafers with notches are more efficient in producing chips.

[0006] Notch groove grinding wheel is a kind of grinding wheel that can be used for high-precision grinding of the groove (notch groove) of semiconductor wafers. In the field of semiconductor wafer processing, notch groove grinding wheels are currently basically dependent on imports, and domestic production has basically not started. Moreover, the existing notch groove grinding wheel, as the sand grains become finer, will affect the service life of the grinding wheel, resulting in a tendency for the service life of the grinding wheel to be shortened.

[0007] Therefore, it is necessary to provide a method for preparing a diamond grinding wheel for wafer Notch groove grinding to solve the above technical problems. Summary of the invention

[0008] The present invention provides a method for preparing a diamond grinding wheel for wafer Notch groove grinding, so as to solve or at least alleviate the above problems.

[0009] According to one aspect of the present invention, there is provided a method for preparing a diamond grinding wheel for wafer Notch groove grinding, comprising: obtaining a plurality of raw materials for the diamond grinding wheel according to a predetermined formula, the plurality of raw materials comprising diamond abrasive, metal binder powder, and additives, the additives comprising one or more of ceramic powder and resin powder; mixing the plurality of raw materials to obtain a mixed material; placing a grinding wheel substrate into a mold, and placing the mixed material into the mold to obtain a mold with a grinding wheel green body; hot pressing and sintering the mold with the grinding wheel green body and keeping it warm, then removing the mold to obtain a grinding wheel blank; processing and trimming the grinding wheel blank to obtain a diamond grinding wheel.

[0010] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the metal binder powder is any one of a Cu-Sn system bronze binder powder, a copper-free binder system powder, and a low copper content binder system powder.

[0011] Optionally, in the preparation method of a diamond grinding wheel for wafer Notch groove grinding according to the present invention, the predetermined formula includes the mass percentage of each raw material of the diamond grinding wheel, wherein the mass percentage of the diamond abrasive is 10%-35%, the mass percentage of the metal binder powder is 65%-85%, and the mass percentage of the additive is 3%-10%.

[0012] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the multiple raw materials of the diamond grinding wheel further include auxiliary materials, and the auxiliary materials include graphite powder or graphite particles; the mass percentage of the auxiliary materials is 1-8%.

[0013] Optionally, in the preparation method of the diamond grinding wheel for wafer Notch groove grinding according to the present invention, multiple raw materials of the diamond grinding wheel are mixed to obtain a mixed material, including: mixing multiple raw materials of the diamond grinding wheel to obtain a mixed powder; spray granulating the mixed powder to obtain a mixed material.

[0014] Optionally, in the preparation method of the diamond grinding wheel for wafer Notch groove grinding according to the present invention, multiple raw materials of the diamond grinding wheel are mixed to obtain a mixed powder, including: using a three-dimensional mixer, mixing the multiple raw materials of the diamond grinding wheel for a predetermined time to obtain a mixed powder; spraying and granulating the mixed powder to obtain a mixed material, including: sieving the mixed powder and adding it into water, and adding a surfactant to stir to obtain a mixed solution; using a spray granulator, spraying and granulating the mixed solution to obtain a mixed material.

[0015] Optionally, in the preparation method of the diamond grinding wheel for wafer Notch groove grinding according to the present invention, the grinding wheel base is placed in a mold, and the mixed material is put into the mold to obtain a mold with a grinding wheel green body, including: placing the grinding wheel base into the mold, and putting the mixed material into the mold, and scraping the mixed material flat, and then installing the upper pressure head of the mold to obtain a mold with a grinding wheel green body.

[0016] Optionally, in the preparation method of the diamond grinding wheel for wafer Notch groove grinding according to the present invention, the mold with the grinding wheel green body is hot pressed and sintered and kept warm, including: placing the mold with the grinding wheel green body into a hot pressing and sintering machine; using the hot pressing and sintering machine, based on a predetermined process curve, to hot press and sinter the mold with the grinding wheel green body and keep warm; wherein the predetermined process curve includes a sintering temperature and a holding time, wherein the sintering temperature is 480-650°C, and the holding time is 3-120min.

[0017] Optionally, in the preparation method of a diamond grinding wheel for wafer Notch groove grinding according to the present invention, the grinding wheel blank includes a grinding wheel base and a diamond layer; the grinding wheel blank is processed and dressed to obtain a diamond grinding wheel, including: first processing the grinding wheel base of the grinding wheel blank, and then processing the diamond layer of the grinding wheel blank to obtain a processed grinding wheel blank; using a dressing tool of an electric discharge machine or an electrolytic grinder to dress the groove surface of the processed grinding wheel blank to obtain a diamond grinding wheel.

[0018] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the particle size of the metal binder powder is 200-5000#.

[0019] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the metal binder powder includes one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P.

[0020] Optionally, in the preparation method of a diamond grinding wheel for wafer Notch grinding according to the present invention, the metal binder powder includes one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P, and the additive is ceramic powder.

[0021] Optionally, in the preparation method of a diamond grinding wheel for wafer Notch grinding according to the present invention, the metal binder powder includes one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P, and the additive is resin powder.

[0022] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the ceramic powder includes one or more of Al2O3, SiC, and SiO2; and the resin powder is polyimide or PBO.

[0023] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the predetermined time length is 30 minutes.

[0024] Optionally, in the method for preparing a diamond grinding wheel for wafer Notch grinding according to the present invention, the material of the wafer is SiC, Si, GaAs, InP, CdTe or GaN.

[0025] According to the technical solution of the present invention, a method for preparing a diamond grinding wheel for wafer Notch groove grinding is provided, wherein diamond abrasive, metal binder powder, and additives are obtained according to a predetermined formula, and a diamond grinding wheel (wafer Notch groove grinding wheel) is prepared through processes such as mixing, hot pressing sintering, processing, and dressing, wherein the metal binder is combined with additives such as ceramic powder and resin powder to enhance the mechanical properties of the metal binder and improve the self-sharpening and sharpness of the wafer Notch groove grinding wheel finally prepared. In this way, the wafer Notch groove grinding wheel prepared according to the present invention can not only realize ultra-precision grinding of the wafer Notch groove, but also significantly improve the service life, and the grinding accuracy of the wafer Notch groove is higher.

[0026] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To achieve the above and related purposes, certain illustrative aspects are described herein in conjunction with the following description and accompanying drawings, which indicate various ways in which the principles disclosed herein can be practiced, and all aspects and their equivalents are intended to fall within the scope of the claimed subject matter. The above and other purposes, features and advantages of the present disclosure will become more apparent by reading the following detailed description in conjunction with the accompanying drawings. Throughout the present disclosure, the same reference numerals generally refer to the same parts or elements.

[0028] Figure 1 A schematic diagram of a wafer groove provided according to an embodiment of the present invention is shown;

[0029] Figure 2 A schematic flow chart of a method 200 for preparing a diamond grinding wheel for wafer Notch grinding according to an embodiment of the present invention is shown;

[0030] Figure 3 A schematic structural diagram of a diamond grinding wheel prepared according to an embodiment of the present invention is shown;

[0031] Figure 4 A schematic diagram of a dressing tool used in some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0032] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0033] In view of the defects of existing grinding wheels when used for wafer Notch groove grinding, the present invention provides a method for preparing a diamond grinding wheel for wafer Notch groove grinding. The diamond grinding wheel is prepared by using a metal binder, a metal-ceramic composite binder or a metal-based resin composite binder in combination with diamond abrasives of corresponding particle sizes through mixing, hot pressing sintering, processing and dressing processes. The diamond grinding wheel can achieve ultra-precision grinding of wafer Notch grooves and improves service life and processing accuracy.

[0034] The following first introduces several binders that can be used for diamond grinding wheels.

[0035] Diamond grinding wheels made from metal binders (such as bronze, iron, nickel, titanium, etc.) have high bonding strength, good forming performance, high temperature resistance, strong wear resistance and impact resistance, good thermal conductivity and wear resistance, long service life, and can withstand large loads. Therefore, they are suitable for grinding operations under high speed, heavy load and high temperature conditions, especially in precision grinding and complex shape grinding, such as the processing of cemented carbide, glass, ceramics, stone and semiconductor materials. However, metal bond grinding wheels have disadvantages such as easy clogging and difficult processing, which affect some of their applications.

[0036] Diamond grinding wheels based on vitrified bonds play an important role in modern industrial grinding due to their high hardness, high wear resistance, high self-sharpening, high shape retention, high temperature resistance, chemical corrosion resistance and high wear resistance. However, diamond grinding wheels based on vitrified bonds have disadvantages such as poor toughness and easy breakage.

[0037] Diamond grinding wheels prepared based on resin bonds are widely used in precision machining of various difficult-to-machine materials due to their high sharpness, good machining surface quality, low molding temperature, and simple equipment. However, the life of diamond grinding wheels prepared based on resin bonds is relatively short.

[0038] Metal-ceramic composite binders and metal-based resin composite binders combine the advantages of metal and ceramic, metal and resin respectively. Diamond grinding wheels prepared based on composite binders have the characteristics of good sharpness, good self-sharpening, long life, high precision, etc., and have good application prospects in the field of semiconductor ultra-precision processing.

[0039] Figure 1A schematic diagram of a wafer notch provided according to an embodiment of the present invention is shown. Figure 2 A schematic flow chart of a method 200 for preparing a diamond grinding wheel for wafer Notch grinding according to an embodiment of the present invention is shown.

[0040] The following will be combined Figure 2 , to describe in detail the preparation method 200 of the diamond grinding wheel for wafer Notch groove grinding of the present invention.

[0041] It should be noted that the diamond grinding wheel to be prepared according to the embodiment of the present invention is specifically a diamond grinding wheel for wafer Notch grinding (hereinafter referred to as "wafer Notch grinding wheel"). Figure 1 In other words, the diamond grinding wheel prepared by the method 200 of the present invention can Figure 1 The wafer grooves shown are processed by ultra-precision grinding.

[0042] like Figure 2 As shown, the method 200 for preparing a diamond grinding wheel for wafer Notch grinding includes the following steps 210-250.

[0043] First, in step 210, a plurality of raw materials for a diamond grinding wheel are obtained according to a predetermined formula, wherein the plurality of raw materials include diamond abrasive, metal binder powder, and additives (ie, second phase reinforcement materials). The additives may include one or more of ceramic powder and resin powder.

[0044] It should be noted that the metal binder is combined with the additive in the embodiment of the present invention, which can enhance the mechanical properties of the metal binder and improve the self-sharpening property of the finally prepared diamond grinding wheel.

[0045] In some embodiments, the metal binder powder used to prepare the diamond grinding wheel can be any one of a copper-free copper binder powder and a copper-free copper binder powder. Specifically, the metal binder powder used to prepare the diamond grinding wheel can include one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P. The additive (second phase reinforcement material) can include one or more of ceramic powder and resin powder.

[0046] In some embodiments, the particle size of the metal binder powder may be 200-5000#.

[0047] It should also be noted that the predetermined formula includes the mass percentage of each raw material of the diamond grinding wheel, and the corresponding mass of the raw materials can be weighed according to the mass percentage of each raw material in the predetermined formula in step 210. In the predetermined formula provided in some embodiments, the mass percentage of the diamond abrasive can be 10%-35%, the mass percentage of the metal binder powder can be 65%-85%, and the mass percentage of the additive can be 3%-10%.

[0048] In some embodiments, the various raw materials of the diamond grinding wheel may include auxiliary materials in addition to diamond abrasives, metal binder powders, and additives. The auxiliary materials may include graphite powder or graphite particles. In the predetermined formula provided in some embodiments, the mass percentage of the auxiliary materials may be 1-8%.

[0049] Subsequently, in step 220, the various raw materials of the diamond grinding wheel obtained in step 210 may be mixed to obtain a mixed material.

[0050] In some embodiments, in step 220, multiple raw materials of the diamond grinding wheel may be mixed to obtain a mixed powder, and the mixed powder may be sieved to obtain a mixed material.

[0051] In some embodiments, in step 220, the various raw materials of the diamond grinding wheel may be first mixed to obtain a mixed powder, and then the mixed powder may be spray granulated to obtain a mixed material with good fluidity (ie, a mixed granulated material).

[0052] In some embodiments, in step 220, various raw materials of the diamond grinding wheel can be placed in a mixing tank, and then a three-dimensional mixer is started, and the three-dimensional mixer is used to mix the various raw materials of the diamond grinding wheel for a predetermined time (that is, the mixing time is a predetermined time) to obtain a mixed powder. For example, the predetermined time is 30 minutes, that is, the three-dimensional mixer can be used to mix the various raw materials of the diamond grinding wheel for 30 minutes to obtain a mixed powder. In a specific embodiment, in the process of mixing the various raw materials of the diamond grinding wheel using the three-dimensional mixer, the rotation speed of the three-dimensional mixer can be controlled to be 20rpm.

[0053] Furthermore, the mixed powder can be spray granulated in the following manner: the mixed powder is sieved and added to water, and a surfactant is added and stirred to obtain a mixed solution. Then, the mixed solution can be pumped into a spray granulator, and the mixed solution is spray granulated by the spray granulator to obtain a mixed material (mixed granulation material). In a specific embodiment, the mixed powder can be sieved through an 80# sieve 3 times, and then added to water, and a surfactant with a mass percentage of 0.5% is added, and then stirred for 15 minutes by an electric stirrer to obtain a mixed solution with a concentration of 15%. Then, the mixed solution can be pumped into a spray granulator, and the mixed solution is spray granulated by the spray granulator to obtain a mixed material (mixed granulation material).

[0054] Next, in step 230, the pre-prepared grinding wheel matrix can be placed in the mold, and the mixed material (appropriate amount of mixed material) obtained in step 220 can be put into the mold to obtain a mold with a grinding wheel green body.

[0055] Specifically, in step 230, the grinding wheel substrate can be first placed in the mold, and then the mixed material can be put into the mold, and the mixed material can be scraped flat, and then the upper pressure head of the mold can be installed, so as to obtain a mold with a grinding wheel green body.

[0056] Next, in step 240, the mold with the grinding wheel blank may be hot-pressed and sintered and kept warm, and then the mold is removed to obtain a grinding wheel blank.

[0057] It should be understood that hot pressing sintering can achieve simultaneous heating while applying pressure, so that the molding and sintering processes are completed simultaneously.

[0058] In some embodiments, in step 240, the specific method of hot pressing and sintering the mold with the grinding wheel green body and keeping it warm is as follows: first, the mold with the grinding wheel green body is placed in a hot pressing and sintering machine, and then, the hot pressing and sintering machine can be used to hot press and sinter the mold with the grinding wheel green body based on a predetermined process curve and keep it warm. Here, the predetermined process curve may include a sintering temperature and a heat preservation time. In some embodiments, the sintering temperature may be 480-650°C, and the heat preservation time may be 3-120min.

[0059] Finally, in step 250, the grinding wheel blank obtained in step 240 may be processed and trimmed to obtain a diamond grinding wheel (ie, a diamond grinding wheel for wafer Notch groove grinding; ie, a wafer Notch groove grinding wheel).

[0060] In the embodiment of the present invention, the material of the wafer may be SiC, Si, GaAs, InP or GaN. That is, the diamond grinding wheel prepared according to the method 200 of the present invention is suitable for ultra-precision grinding of notches of various wafers including semiconductor materials such as SiC, Si, GaAs, InP, CdTe, GaN, etc.

[0061] It should be noted that the grinding wheel blank includes a grinding wheel base and a diamond layer.

[0062] Figure 3 Shown is a schematic structural diagram of a diamond grinding wheel prepared according to an embodiment of the present invention. Figure 4 A schematic diagram of a dressing tool used in some embodiments of the present invention is shown.

[0063] In some embodiments, when the grinding wheel blank is processed and trimmed in step 250, the grinding wheel base of the grinding wheel blank may be processed first, and then the diamond layer of the grinding wheel blank may be processed to obtain the processed grinding wheel blank. Figure 3 and Figure 4 As shown, according to the groove type of the diamond grinding wheel to be prepared, the dressing tool of the electric spark machining machine or the electrochemical grinder (see Figure 4 A dressing tool (shown) is used to dress the groove surface of the machined grinding wheel blank to obtain a diamond grinding wheel.

[0064] According to the method 200 for preparing a diamond grinding wheel for wafer Notch groove grinding provided by an embodiment of the present invention, a metal binder is combined with additives such as ceramic powder and resin powder, which can enhance the mechanical properties of the metal binder and improve the self-sharpening and sharpness of the wafer Notch groove grinding wheel finally prepared. In this way, the wafer Notch groove grinding wheel prepared according to the present invention can not only realize ultra-precision grinding of the wafer Notch groove, but also significantly improve the service life and achieve higher precision in grinding the wafer Notch groove.

[0065] In some embodiments, among the various raw materials of the diamond grinding wheel obtained in step 210, the metal binder powder includes Cu powder and Sn powder. That is, based on the bronze binder (Cu powder and Sn powder) of the Cu-Sn system, Ti or Ni metal elements may be added. This can improve the toughness and strength of the metal binder, and at the same time improve the wettability of the metal binder to diamond.

[0066] In some embodiments, among the various raw materials of the diamond grinding wheel obtained in step 210, the metal binder powder is Cu3Sn powder, and the additive is ceramic powder. That is, based on the bronze binder (Cu3Sn powder) of the Cu-Sn system, ceramic powder is added to form a metal-ceramic composite binder. The diamond grinding wheel prepared based on the metal-ceramic composite binder can improve self-sharpening performance.

[0067] In some embodiments, among the various raw materials of the diamond grinding wheel obtained in step 210, the metal binder powder includes Ti powder, Ni powder, Sn powder, and the additive is resin powder. That is, based on the metal binder (Ti powder, Al powder, Sn powder), resin powder is added to form a metal-based resin composite binder. The diamond grinding wheel prepared based on the metal-based resin composite binder can improve self-sharpening performance.

[0068] In the above embodiments, the ceramic powder may include one or more of Al2O3, SiC, and SiO2. The resin powder may be polyimide (PI) or PBO.

[0069] The material composition and process parameters involved in the preparation of diamond grinding wheels will be described in detail below through three specific embodiments (first embodiment, second embodiment, and third embodiment).

[0070] In the first embodiment, various raw materials and parameters (including particle size and mass percentage) of the diamond grinding wheel obtained according to a predetermined formula are specifically shown in Table 1 below.

[0071] Table 1 Various raw materials and parameters of diamond grinding wheel in the first embodiment

[0072]

[0073] Referring to Table 1, in the first embodiment, a copper-tin bronze binder (Cu powder and Sn powder) of the Cu-Sn system is used as the basis, and a Ti metal element is added to improve the toughness and strength of the metal binder, and at the same time improve the wettability of the metal binder to diamond.

[0074] Subsequently, the above-mentioned various raw materials can be put into a mixing tank, and then the three-dimensional mixer is started, and the rotation speed of the three-dimensional mixer is controlled to be 20rpm, and the three-dimensional mixer is used to mix the various raw materials of the diamond grinding wheel for 30 minutes to obtain a mixed powder. Then, the mixed powder is taken out from the mixing tank, and the mixed powder is sieved through an 80# sieve three times to obtain a mixed material.

[0075] Next, the graphite mold can be assembled, the grinding wheel substrate (steel substrate) can be placed in the mold, and then an appropriate amount of mixed material (the mixed material required for a single diamond grinding wheel, with a mass of 13.96g) can be weighed and put into the mold, and the mixed material can be scraped flat, and then the upper pressure head of the mold can be installed to obtain a mold with a grinding wheel green body.

[0076] Next, the mold with the grinding wheel blank can be placed in a vacuum hot pressing sintering machine, and then the vacuum hot pressing sintering machine is used to hot press and sinter the mold with the grinding wheel blank based on a predetermined process curve, and the heat preservation is performed. Specifically, the sintering temperature of the predetermined process curve is 530°C, and the heat preservation time is 3 minutes. After that, the mold is taken out of the vacuum hot pressing sintering machine, and the mold is unloaded to obtain a grinding wheel blank.

[0077] Finally, the grinding wheel blank can be machined to complete the rough turning and rough grinding to obtain the processed grinding wheel blank. Then, the dressing tool (such as Figure 4 As shown in the figure, the groove surface of the processed grinding wheel blank is trimmed (discharge machining) to obtain the final diamond grinding wheel (wafer Notch groove grinding wheel).

[0078] The diamond grinding wheel prepared according to the first embodiment can process 30 8" SiC wafer Notch grooves. The processing results are shown in Table 2 below.

[0079] Table 2 Processing results of diamond grinding wheels prepared in the first embodiment

[0080] parameter Measured average value Reference value V 1.15mm 1.0mm-1.25mm VxD 86.58° 85-95° life 30 items

[0081] In the second embodiment, various raw materials and parameters (including particle size and mass percentage) of the diamond grinding wheel obtained according to the predetermined formula are specifically shown in Table 3 below.

[0082] Table 3 Various raw materials and parameters of diamond grinding wheel in the second embodiment

[0083]

[0084] Referring to Table 3, in the second embodiment, a copper-based binder (Cu3Sn powder) of the Cu-Sn system is used as the basis, and ceramic powder is added to form a metal-ceramic composite binder. The diamond grinding wheel prepared based on the metal-ceramic composite binder can improve self-sharpening properties.

[0085] Subsequently, the above-mentioned various raw materials can be put into a mixing tank, and a three-dimensional mixer can be started, and the rotation speed of the three-dimensional mixer can be controlled to be 20rpm. The three-dimensional mixer can be used to mix the various raw materials of the diamond grinding wheel for 30 minutes to obtain a mixed powder. Then, the mixed powder is taken out from the mixing tank, the mixed powder is sieved through an 80# sieve 3 times, and then added to water, and a surfactant with a mass percentage of 0.5% is added at the same time, and then stirred for 15 minutes by an electric stirrer to obtain a mixed solution with a concentration of 15%. After that, the mixed solution can be pumped into a spray granulator, and the mixed solution can be spray granulated by a spray granulator. Then, spherical particles with a diameter of 40-50 microns are obtained from the spray granulator and placed in a mortar, and paraffin with a mass percentage of 1.5% is added as a wetting agent. After stirring in the mortar, a mixed material (mixed granulation material) can be obtained.

[0086] Next, the steel mold can be assembled, the grinding wheel substrate (steel substrate) can be placed in the mold, and then an appropriate amount of mixed material (the mixed material required for a single diamond grinding wheel, with a mass of 12.4g) can be weighed and put into the mold, and the mixed material can be scraped flat, and then the upper pressure head of the mold can be installed, so that a mold with a grinding wheel green body can be obtained.

[0087] Next, the mold with the grinding wheel blank can be pre-pressed by a cold press, and then the pre-pressed mold with the grinding wheel blank is placed in a hot press sintering machine. The hot press sintering machine is used to hot press and sinter the mold with the grinding wheel blank based on a predetermined process curve and keep it warm. Specifically, the sintering temperature of the predetermined process curve is 580°C and the insulation time is 120 minutes. After the insulation is completed, the mold is immediately taken out of the hot press sintering machine, and then pressed at a pressure of 150MPa. When the upper pressure ring and the mold sleeve are flush, the pressure is maintained for 1 minute, and it is naturally cooled to about 100 degrees. Then the mold is removed to obtain a grinding wheel blank.

[0088] Finally, the grinding wheel blank can be machined to complete the rough turning and rough grinding to obtain the processed grinding wheel blank. Then, the dressing tool (such as Figure 4 As shown in the figure, the groove surface of the processed grinding wheel blank is trimmed (discharge machining) to obtain the final diamond grinding wheel (wafer Notch groove grinding wheel).

[0089] The diamond grinding wheel prepared according to the second embodiment can process 50 8" SiC wafer Notch grooves. The processing results are shown in Table 4 below.

[0090] Table 4 Processing results of diamond grinding wheel prepared in the second embodiment

[0091] parameter Measured average value Reference value V 1.05mm 1.0mm-1.25mm VxD 90.05° 85-95° life 50 items

[0092] In the third embodiment, various raw materials and parameters (including particle size and mass percentage) of the diamond grinding wheel obtained according to the predetermined formula are specifically shown in Table 5 below.

[0093] Table 5 Various raw materials and parameters of diamond grinding wheel in the third embodiment

[0094]

[0095] Referring to Table 5, in the third embodiment, a metal binder (Ti powder, Ni powder, Sn powder, etc.) is used as the basis, and resin powder is added to form a metal-based resin composite binder. The diamond grinding wheel prepared based on the metal-based resin composite binder can improve self-sharpening performance.

[0096] Subsequently, the above-mentioned various raw materials can be put into a mixing tank, and then the three-dimensional mixer is started, and the rotation speed of the three-dimensional mixer is controlled to be 20rpm, and the three-dimensional mixer is used to mix the various raw materials of the diamond grinding wheel for 30 minutes to obtain a mixed powder. Then, the mixed powder is taken out from the mixing tank, and the mixed powder is sieved through an 80# sieve three times to obtain a mixed material.

[0097] Next, the graphite mold can be assembled, the grinding wheel substrate (steel substrate) can be placed in the mold, and then an appropriate amount of mixed material (the mixed material required for a single diamond grinding wheel, with a mass of 13.42g) can be weighed and put into the mold, and the mixed material can be scraped flat, and then the upper pressure head of the mold can be installed, so that a mold with a grinding wheel green body can be obtained.

[0098] Next, the mold with the grinding wheel blank can be placed in a vacuum hot pressing sintering machine, and then the vacuum hot pressing sintering machine is used to hot press and sinter the mold with the grinding wheel blank based on a predetermined process curve, and the heat preservation is carried out. Specifically, the sintering temperature of the predetermined process curve is 480°C, and the heat preservation time is 3 minutes. After that, the mold is taken out of the vacuum hot pressing sintering machine, and the mold is unloaded to obtain a grinding wheel blank.

[0099] Finally, the grinding wheel blank can be machined to complete the rough turning and rough grinding to obtain the processed grinding wheel blank. Figure 4 As shown in the figure, the groove surface of the processed grinding wheel blank is trimmed (electrolytic machining) to obtain the final diamond grinding wheel (wafer Notch groove grinding wheel).

[0100] The diamond grinding wheel prepared according to the third embodiment can process 60 8" SiC wafer Notch grooves. The processing results are shown in Table 6 below.

[0101] Table 6 Processing results of diamond grinding wheel prepared in the third embodiment

[0102] parameter Measured average value Reference value V 1.05mm 1.0mm-1.25mm VxD 88.95° 85-95° life 60 items

[0103] It can be seen that the service life of the diamond grinding wheels prepared in the above three embodiments is significantly improved. Among them, in the third embodiment, the service life of the diamond grinding wheel prepared by the metal-based resin composite binder based on Ti powder, Al powder, Sn powder and resin powder is the highest.

[0104] The above is only an explanation of a specific implementation example of the present invention. It should be pointed out that the formula and process involved in the preparation method 200 of the diamond grinding wheel for wafer Notch groove grinding of the present invention are not limited to the specific parameters described in the above embodiment.

[0105] In addition, the embodiment of the present invention also discloses: A11, a method as described in any one of A1-A10, wherein the metal binder powder includes one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P. A12, a method as described in any one of A1-A10, wherein the metal binder powder includes one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P, and the additive is ceramic powder. A13, a method as described in any one of A1-A10, wherein the metal binder powder includes one or more of Cu powder, Sn powder, Ti powder, Ni powder, Fe powder, Cu3Sn, TiH2, and Cu3P, and the additive is resin powder. A14, a method as described in any one of A1-A13, wherein the ceramic powder includes one or more of Al2O3, SiC, and SiO2; and the resin powder is polyimide or PBO. A15, a method as described in A6, wherein the predetermined time length is 30 minutes. A16. A method as described in any one of A1-A15, wherein the material of the wafer is SiC, Si, GaAs, InP, CdTe or GaN.

[0106] In summary, according to the preparation method 200 of the diamond grinding wheel for wafer Notch groove grinding of the present invention, diamond abrasive, metal binder powder, and additives are obtained according to a predetermined formula, and a diamond grinding wheel (wafer Notch groove grinding wheel) is prepared through mixing, hot pressing sintering, processing and dressing processes, wherein the metal binder is combined with additives such as ceramic powder and resin powder to enhance the mechanical properties of the metal binder and improve the self-sharpening and sharpness of the wafer Notch groove grinding wheel finally prepared. In this way, the wafer Notch groove grinding wheel prepared according to the present invention can not only realize ultra-precision grinding of the wafer Notch groove, but also significantly improve the service life, and the precision of the wafer Notch groove grinding is higher.

[0107] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0108] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof.

[0109] Those skilled in the art should understand that the modules or units or components of the device in the examples disclosed herein may be arranged in the device as described in the embodiment, or alternatively may be located in one or more devices different from the device in the example.

[0110] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and furthermore may be divided into a plurality of submodules or subunits or subcomponents.

[0111] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present invention and to form different embodiments.

[0112] As used herein, unless otherwise specified, the use of ordinal numbers "first," "second," "third," etc. to describe common objects merely indicates that different instances of similar objects are involved, and is not intended to imply that the objects so described must have a given order in time, space, order, or in any other manner.

[0113] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is primarily selected for readability and instructional purposes, rather than for explaining or limiting the subject matter of the present invention.

Claims

1. A method for preparing a diamond grinding wheel for wafer Notch grinding, comprising: Obtaining a variety of raw materials for a diamond grinding wheel according to a predetermined formula, wherein the various raw materials include diamond abrasives, metal binder powder, and additives, wherein the additives include one or more of ceramic powder and resin powder; Mixing the multiple raw materials to obtain a mixed material; Putting a grinding wheel matrix into a mold, and placing the mixed material into the mold to obtain a mold with a grinding wheel green body; After hot pressing and sintering the mold with the grinding wheel green body and keeping it warm, the mold is removed to obtain a grinding wheel blank; The grinding wheel blank is processed and dressed to obtain a diamond grinding wheel.

2. The method of claim 1, wherein: The metal binder powder is any one of a copper-Sn bronze binder powder, a copper-free binder powder, and a low-copper-content binder powder.

3. The method according to claim 1 or 2, wherein: The predetermined formula includes the mass percentage of each raw material of the diamond grinding wheel, wherein the mass percentage of the diamond abrasive is 10%-35%, the mass percentage of the metal binder powder is 65%-85%, and the mass percentage of the additive is 3%-10%.

4. The method according to any one of claims 1 to 3, wherein: The various raw materials of the diamond grinding wheel also include auxiliary materials, and the auxiliary materials include graphite powder or graphite particles; The mass percentage of the auxiliary material is 1-8%.

5. The method according to any one of claims 1 to 4, wherein: The various raw materials of the diamond grinding wheel are mixed to obtain a mixed material, including: Mixing a plurality of raw materials of the diamond grinding wheel to obtain mixed powder; The mixed powder is subjected to spray granulation to obtain a mixed material.

6. The method of claim 5, wherein: The various raw materials of the diamond grinding wheel are mixed to obtain a mixed powder, including: Using a three-dimensional mixer, mixing the various raw materials of the diamond grinding wheel for a predetermined time to obtain a mixed powder; The mixed powder is spray-granulated to obtain a mixed material, comprising: The mixed powder is sieved and added into water, and a surfactant is added and stirred to obtain a mixed solution; The mixed solution is spray-granulated by using a spray granulator to obtain a mixed material.

7. The method according to any one of claims 1 to 6, wherein: The method comprises placing a grinding wheel matrix into a mold, and placing the mixed material into the mold to obtain a mold with a grinding wheel green body, comprising: The grinding wheel matrix is ​​placed in the mold, the mixed material is placed in the mold, and the mixed material is scraped flat, and then the upper pressure head of the mold is installed to obtain a mold with a grinding wheel green body.

8. The method according to any one of claims 1 to 7, wherein: The mold with the grinding wheel green body is hot pressed and sintered and kept warm, comprising: Putting the mold with the grinding wheel green body into a hot pressing sintering machine; Using the hot pressing sintering machine, based on a predetermined process curve, hot pressing and sintering the mold with the grinding wheel green body and keeping it warm; The predetermined process curve includes a sintering temperature and a holding time, wherein the sintering temperature is 480-650° C., and the holding time is 3-120 min.

9. The method according to any one of claims 1 to 8, wherein: The grinding wheel blank comprises a grinding wheel matrix and a diamond layer; The grinding wheel blank is processed and trimmed to obtain a diamond grinding wheel, comprising: Firstly, the grinding wheel base of the grinding wheel blank is processed, and then the diamond layer of the grinding wheel blank is processed to obtain a processed grinding wheel blank; The groove surface of the processed grinding wheel blank is dressed by using a dressing tool of an electric spark machining machine or an electrochemical grinder to obtain a diamond grinding wheel.

10. The method according to any one of claims 1 to 9, wherein: The particle size of the metal binder powder is 200-5000#.

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